Micrometer.



11.15;. 153 5 f u i PATENTED NOV. 6, 1906.

D. K. LEE.

MICROMETBR.

APPLICATION FILED D3015. 1905.

. .i lliiizlilllu LIiE i INVENTOR WITNESSES:

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To all 11:7: 0m it may concern..-

Be it known that 1, DAY K. LEE, a citizen of the United States, residingat Athens, in the county of Bradford and State of Pennsylvania, haveinvented certain new and useful Improvements in .\licrometers, ofwhich'the following is a specification.

This invention relates to improvements in micrometer-gages for insidecalipering; and my object is to provide a micrometer which shall beadapted to measuring small diameters and which maybe readily andaccuratclv adjusted for measuring larger or smaller diameters within itsrange.

A further object is to provide a micrometer of this type which will besimple in construction and which may be manufactured at a small cost andyet be accurate in its measurements.

I attain my object by constructing the micrometer in the mannerillustrated in the accompanying drawings, in which Figure 1 represents aside elevation of I11; improved micrometer; Fig. ".2, a plan viewthereof; Fig. 3, a partial side elevation showing the device foradjusting the micrometerpin, and F 4 a plan view of Fig) 3.

Like letters o reference designate like parts in the several views.

The stock or handle A of the micrometer is given the form illustrated inFigs. 1 and 2 and is provided at the outer end with a clamping-jawlll'fl) which is screwed an adjustable pin B, the inner end of said pinbeing adjustable along the scale C, formed on the stock of themicrometer below the threaded jaws. The stock is longitudinally slottedon the under side, and in this slot is ivoted an arm D by means of thepivot-pin E The outer end of this arm is provided with a caliper-pointat F, which stands in line with the axis of the pin B, and the inner endof the arm D is engaged by an adjustingsorew G, which is rotated toadjust the arm by means of a graduated thumb-wheel H. the adjustment ofwhich wheel is ascertained by the position of its upper surface and itsgleduations with reference to the index-finger l, which rises from thestock A. The arm D is held in engagement with the adjusting-screw b Tmeans of a spring J which straddles tie handle portion of the stock Aand is fastened thereto and held in place by a pair of pins, as shown inF ig. 1.

The pivotal point E of the arm D is set ata.

Specification of Letters Patent.

. inn .sTATns nirnv" oFF oE.

MICROMETER.

Patented Nov. 6, 1906.

Application filed December 15,1905. Serial No. 291,846.

distancefrom the bearing-point of the adjusting screwG equal to two andone-half times the distance from the pivotal point to the caliper-pointF. l 11 other words, the micrometer-arm is divided by its pivotal pointin the raio of two and one-half to one. The threads on theadjusting-screw G in theinst-rument herein illustrated are cut to apitch of forty to the inch, so that one complete rotation of the screwto the right or left will cause the inner end of the arm D to moveoutwardly or inwardly to the extent of onefortieth of an inch, andconsequently there will be transmitted to the caliper-point F a movementin a relatively opposite direction of one one-hundredth of an inch. Theface of the thumb-wheel H is divided into ten equal parts by suitablegraduating-marks, one of said graduations being marked O and the othersbeing marked from 1 to .9, or, if desired, only the graduationdiametrically opposite the zero-point, which is 5 on the scale, need bemarked. hen the caliperpoint F is in its mid-position, the upper surfaceof the thumb-wheel H level with the top of the index-finger I and thezero-point on the thumb-wheel will register with said index. If nowthethu1nb wheel is turned one'point to the right or left, it will beunderstood that the caliper-point F will be moved correspondingly towardor away from the pin B to the extent of onetenth of one one-hundredth ofan inch, or one one-thousandth of an inch. Therefore if the pin B be ofsuch a length that its oint will lie exactly one inch from the point Fwhen the arm D is in its mid-position then inside diameters of an inch,more or less, maybe measured accurately to the one onethousandth of aninch by turning the thumbwheel H in one direction or the other andnoting the position of its graduations with reference to the index I. Ifthe thumbwheel is turned to the right, its upper surface will fall belowthe top of the indexIand will indicate that the caliper-point F ismoving toward the pin B, and therefore measuring a diameter less thanone inch. If, on the other hand, the thumb-wheel be turned to the left,its u per surface will rise above the index' I and will indicate acaliper of more than one inch.

If the )in B is of such a length that its point wilf stand one inch fromthe caliperpoint F when its inner end registers with the will stand onazero-mark on the scale C-that is to say, the I order to produceadjustments of one onegraduation which lies nearest the point F then byscrewing said pin outwardly its point may be moved outwardly a distanceequal to one-fourth of an inch, as the s ale C is shown on themicrometer as herein illustrated, and the range of the micrometer withsuch a pin will be from oneinch up to one and one-fourth inches, withadditional one one-thousandths of an inch equal to the amount of adjust-ment permissible at the point F. In theinstrument ierein shown theth' .b-wheel H may be rotated two and one-half revolitions in eitherdirection, and therefore the caliper-point F may be moved toward or awayfrom the pin B a distance equal to one-fortieth of an inch in eitherdirection. By supplying the instrument with pins B of different lengths,each pin in a set being two-tenths of an inch onger than the nextshorter pin, the micrometer may be set for calipering diameters fromfive-eighths of an inch or less upward.

To adjust the pin B, I provide a removable graduated disk L, which isadapted to he slipped upon the pin B, said pin having a flattened side,so that the disk may be placed in turning engagement therewith. If thethreads on the pin B are cut to a pitch of forty to the inch, then thegraduations on the disk L will run from zero to 25, and the rotation ofthe disk in one di ection or the other one point will cause the pin tobe moved inwardly or outwardly one one-thousandths of an inch. For quickadjustment, however, the scale C may be used, the movement of the innerend of the pin along said scale indicating an extension or contractionof onefortieth of an inch for each point on the scale. For the purposeof setting the disk L, I provide an index-finger M, which is pivoted tothe side of the stock A so as to be thrown down out of the way after thepin has been adjusted, as shown in Fig. 1 of the drawings.

Instead of using the form of spring J illustrated in Fig. '1 for holdingthe arm D against the end of the adjusting-screw G, I

- may provide a coiled spring, as shown at K place, or I in Fig. 3, saidspring bearing against the outer end of the arm D and being completelyconcealed by the stock A when said arm is in may use both the spring Jand the spring K in order to produce a pressure upon the arm I) whichwill always insure its engagement with the adjusting-screw G, andconsequently a perfect adjustment of the micrometer.

It will of course be understood that the different parts of mymicrometer may be differently proportioned one to another and that thethread pitches on the adjustingscrew and caliper-pin may be other thanforty to the inch, in which case the graduations on the thumb-wheel andadjusting-disk will be made to correspond to such pitch in thousandth ofan inch in the caliper-points.

hat I claim as my invention, and desire to secure by Letters Patent, is-

1. A micrometer for inside calipering comprising a stock or handleprovided at one end with a lat erally-proj ecting fixed caliper-point,means for adjusting said point on the stock to different indicateddiameters, an arm pivotally mounted between its ends upon the stock, acaliper-point at one end of said arm in alinement with and set in theopposite direction from said stationary point, an adjustingscrew on thestock engaging the other end of the arm to impart angular movementthereto, a graduated wheel onsaid screw, and an index on the stockadjacent the wheel, whereby the angular movements of the screw may beread to determine the adjustment of the caliper-point carried by saidarm, the two caliperpoints being at known distances apart when the wheelis at zero.

2. A micrometer for inside oalipering comprising a stock or handle, ascrew-threaded caliper-pin held in a threaded socket at one end thereofand projecting laterally therefrom, means for setting said pin fordifferent determinate diameters, an arm pivotally mounted on the stockand having a caliperpoint at one end in alinement with and set in theopposite direction from said pin, an ad justing-screw on the stock forimparting angular movement to said arm, and a graduated wheel on saidscrew for determining the adjustment of the caliper-point carried bysaid arm.

3. A micrometei for inside calipering comprising a stock or handle, ascrew-threaded caliper-pin held in a threaded socket at one end thereofand projecting laterally therefrom, a scale at one side of said pinalong which its rearward end travels and whereby the pin may be set fordifferent determinate diameters, a movable caliper-point in alinementwith said pin, and means for reading the adjustment of said movablepoint.

4. A micrometer comprising a stock or handle, a screw-threadedcaliper-pin held in a threaded socket at one end thereof and projectinglaterally therefrom, a removable graduated disk adapted to be placedupon said pin in turning engagement therewith, an index on the stockwhereby said disk may be set to indicate the lateral movements of thepin due to partial rotations thereof, a movable caliper-point inalinement with said pin, and means for readmg the adjustment of saidmovable point.

In testimony whereof I have affixed my signature in presence of twowitnesses.

DAY K. LEE.

Witnesses G. M. TOZER, GEO. H. Dovn.

